'\" te
.\" Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved.
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
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.TH PCI_SAVE_CONFIG_REGS 9F "Jun 02, 2000"
.SH NAME
pci_save_config_regs, pci_restore_config_regs \- save and restore the PCI
configuration registers
.SH SYNOPSIS
.nf
\fB#include <sys/ddi.h>\fR
\fB#include <sys/sunddi.h>\fR



\fBint\fR \fBpci_save_config_regs\fR(\fBdev_info_t *\fR\fIdip\fR);
.fi

.LP
.nf
\fBint\fR \fBpci_restore_config_regs\fR(\fBdev_info_t *\fR\fIdip\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI-specific (illumos DDI).
.SH ARGUMENTS
.ne 2
.na
\fB\fIdip\fR\fR
.ad
.RS 7n
Pointer to the device's \fBdev_info\fR structure.
.RE

.SH DESCRIPTION
\fBpci_save_config_regs()\fR saves the current configuration registers on
persistent system memory. \fBpci_restore_config_regs()\fR restores
configuration registers previously saved by \fBpci_save_config_regs()\fR.
.sp
.LP
\fBpci_save_config_regs()\fR should be called by the driver's \fBpower()\fR
entry point before powering a device off (to PCI state D3). Likewise,
\fBpci_restore_config_regs()\fR should be called after powering a device on
(from PCI state D3), but before accessing the device. See \fBpower\fR(9E).
.SH RETURN VALUES
\fBpci_save_config_regs()\fR and \fBpci_restore_config_regs()\fR return:
.sp
.ne 2
.na
\fB\fBDDI_SUCCESS\fR\fR
.ad
.RS 15n
Operation completed successfully.
.RE

.sp
.ne 2
.na
\fB\fBDDI_FAILURE\fR\fR
.ad
.RS 15n
Operation failed to complete successfully.
.RE

.SH CONTEXT
Both these functions can be called from user or kernel context.
.SH EXAMPLES
\fBExample 1 \fRInvoking the save and restore functions
.sp
.in +2
.nf
static int
xx_power(dev_info_t *dip, int component, int level) {
   struct xx *xx;
   int rval = DDI_SUCCESS;

   xx = ddi_get_soft_state(xx_softstate, ddi_get_instance(dip));
   if (xx == NULL) {
       return (DDI_FAILURE);
   }

   mutex_enter(&xx\(mi>x_mutex);

   switch (level) {
   case PM_LEVEL_D0:
       XX_POWER_ON(xx);
       if (pci_restore_config_regs(dip) == DDI_FAILURE) {
           /*
            * appropriate error path handling here
            */
           ...
           rval = DDI_FAILURE;
           }
       break;

   case PM_LEVEL_D3:
       if (pci_save_config_regs(dip) == DDI_FAILURE) {
            /*
             * appropriate error path handling here
             */
            ...
            rval = DDI_FAILURE;
            }
        else {
            XX_POWER_OFF(xx);
        }
        break;

    default:
          rval = DDI_FAILURE;
          break;
    }

    mutex_exit(&xx\(mi>x_mutex);
    return (rval);
}
.fi
.in -2

.SH ATTRIBUTES
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Committed
.TE

.SH SEE ALSO
.BR attributes (7),
.BR power (9E)
.sp
.LP
\fIWriting Device Drivers\fR
.sp
.LP
\fIPCI Bus Power Management Interface Specification Version 1.1\fR
.sp
.LP
\fIPCI Bus Specification Revision 2.1\fR
